Face-Off: The Kraken X61, Reserator 3 Max Dual, And NH-D15

Moving Up To LGA 2011-v3

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We've been drawing comparisons between closed-loop liquid coolers and socket-mounted heat sinks for years, and the reasons for picking one or the other have grown in proportion to cooler size.

It might seem, then, that big heat sinks win the debate before we even start testing, and that closed-loop coolers need to significantly outperform big heat sinks in order to justify their existence. Yet, most of our tests conclude that there’s no performance gain in adding a pump to your cooling system when the radiator is no larger than the heat sink it replaces. Why would anyone even bother with closed loops, then?

A look at today’s contenders reveals at least two of those answers!

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CPU Cooler Features
Air Cooler SpecificationsNoctua NH-D15Liquid Cooler SpecificationsNZXT Kraken X61Zalman Reserator -3 Max Dual
Height6.4"Thickness1.1" (2.2" w/fans)3" (Combined)
Width6.0"Width5.5"5.5" w/Brackets
Depth5.3" (6.4" w/fan)Depth12.3"10.8"
Base Height1.7"Pump Height1.3"1.5"
Assy. OffsetNone (1.1" w/fan)ControllerSoftwareNone
Cooling Fans(2) 150 x 25mmCooling Fans(2) 140 x25mm(2) 120 x 25mm
Connectors(2) 4-PinConnectorsUSB/SATA/3-PIN1x 4-Pin, 1x 3-Pin
Weight48 OuncesWeight45 Ounces48 Ounces
Intel Sockets115x, 2011Intel Sockets115x, 2011, 1366115x, 2011, 1366
AMD Sockets4-bolt RectangularAMD Sockets4-bolt Rectangular4-bolt Rectangular
WarrantySix YearsWarrantySix YearsOne Year
Web Price$95Web Price$140$140

Who would hang a three-pound cooler off their processor interface, knowing that it’s going to turn into a wrecking ball as soon as the machine gets shipped somewhere? We’ve seen smaller coolers than these break off from the motherboard, smashing surrounding components. That’s a lot of equipment to lose.

And then there’s the matter of clearance. System builder and graphics guru Don Woligroski was forced to take a hacksaw to his high-end memory in order to fit a big CPU cooler into his System Builder Marathon machine. That move earned him the temporary title Hacksaw Don, and the fact that I actually specified DIMM clearance (base height, thickness and assembly offset) in my review of the cooler he used erased any sympathy he might have otherwise garnered.

The only reason we often see “big air” in our System Builder Marathon configurations is because it’s cheaper. Whenever large heat sinks are big enough to outperform closed-loop liquid, we’re left warning readers that their PCs must be handled gingerly. We’ve even been forced to disassemble our completed boxes prior to shipping after one of our winners fell victim to the wrecking-ball effect on a cooler less than half this size.

All of this means that a performance win by Noctua’s NH-D15 would necessitate a flurry of caveats in our final recommendations. NZXT and Zalman better step up!

Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.